Queen Camilla is not attending the funeral of Katharine, the Duchess of Kent, as she is recovering from acute sinusitis."With great regret, Her Majesty The Queen has withdrawn from attendance at this afternoons Requiem Mass for The Duchess of Kent as she is recovering from acute sinusitis," Buckingham Palace said in a statement to Fox News Digital on Tuesday. "Her thoughts and prayers will be with The Duke of Kent and all the family."The Queen had traveled down from Scotland this morning to honor Katharine who died earlier this month at the age of 92 and is currently resting at Windsor. King Charles and other senior royals attended the funeral at Westminster Cathedral.BRITISH ROYAL KATHARINE, DUCHESS OF KENT, DEAD AT 92Pending her recovery, Her Majesty plans to attend all elements of the state visit with President Donald Trump on Wednesday.President Trump and first lady Melania Trump are expected to arrive at Windsor Castle on the morning of Sept. 17, where they will be officially greeted by the Prince and Princess of Wales. Prince William and Kate Middleton will then accompany them to meet King Charles and Queen Camilla.In July, Buckingham Palace announced that the Trumps would pay a state visit to the U.K. from Sept. 17-19. King Charles III will host the couple at Windsor Castle.LIKE WHAT YOURE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWSRoyal expert Richard Fitzwilliams told Fox News Digital that the Princess of Wales will be a key player as she supports the monarch and her husband, heir to the British throne. British broadcaster and photographer Helena Chard agreed, telling Fox News Digital that everyone is in good spirits knowing Kate will "play a pivotal role during the state visit.""It marks a pivotal moment in putting Catherine on the world stage," he said. "It marks a turning point with Catherine making more high-profile appearances during this state visit, which is of the utmost importance to Britain, adding an extra special cachet."CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER"Hopefully, it will not be too long before the Waleses can go on tour abroad," Fitzwilliams said. "This is something that will be of enormous interest worldwide."Previously, a formal invitation, known as a "manu regia," was signed by Charles and hand-delivered by British officials to the White House, inviting Trump for a state visit."His Majesty has known President Trump for many years and looks forward to hosting him and the first lady later this year," a palace aide said.Fox News Digital's Stephanie Nolasco and Ashley Papa contributed to this post.